1. Field
The field of the invention is apparatus for preparing and grooming snow slopes for skiing, and more particularly devices for finally smoothing the snow after tilling or other initial preparation.
2. State of the Art
Various snow grooming devices have been used to smooth and recondition the snow of ski slopes. These are generally drawn over the snow behind a tracked vehicle, which often carries a forward blade for preliminary leveling of the snow. Harrows, discs, rollers, snow compacting bars and tillers are examples of these devices. Perhaps the most widely used are the snow tillers, which are powered to aggressively break up and cut snow which is excessively packed from extended use or weather conditions. While it is not "powder", tilled snow is in the form of relatively small aggregated pieces, and when lightly but firmly packed provides easy, enjoyable skiing. Tillers commonly in use have blades on rotating cutter bars covered by a hood with its trailing portion or edge positioned near the snow surface to smooth and compact the cut and chopped snow. Initially, the metallic edge of the skirt was relied upon, and no further conditioning of the snow was provided. Later, a flexible, a saw-toothed-edged member was attached to the skirt trailing edge, such as member 33 disclosed in U.S. Pat. No. 4,359,831. Positioned to bear forceably upon the snow, the trailing edge comb structure 33 further crushed and reduced snow lumps and the like, considerably improving the final surface for skiing. Subsequently, more elaborate devices were employed in the skirt trailing edge area. Instead of the short, saw-tooth member, devices of much greater length proved advantageous. These members bore forcibly downward upon the snow over an increased area of contact, and more effectively powdered the snow. The sawtooth edge comb teeth evolved into parallel ridges, elongate in the direction of travel, bearing generally horizontally upon the snow. Powdering was improved by the ridges. Later, a second and then a third row were used, the individual ridges axially aligned from row to row. The ridges of each row were of equal length and were positioned side by side. A substantial space was provided between succeeding rows, allowing increased flexibility for more extended snow contact. However, even the best of these prior art final grooming combs produced snow surfaces more grooved, more ridged, and harder than was desirable. With some snow conditions, these ridges were so pronounced and rigid as to seize the edges of skis, causing falls and the like. Clearly, although the prior art final grooming devices had been improved considerably, further improvement was needed for safer, more enjoyable skiing.